ANTISEPTIC SOAP BAR

PAIN DE SAVON ANTISEPTIQUE

English Abstract

An antiseptic soap bar comprising: a) 0.35 to 0.75 % w/w of an antimicrobially
active chlorinated methyl substituted phenol; b) 0.15
to 0.25 % w/w triclosan (or a salt thereof); and c) less than 0.075 % w/w EDTA
chelating agents.

French Abstract

L'invention concerne un pain de savon antiseptique comprenant: a) entre 0,35 et 0,75 % en poids d'un phénol substitué par du méthyle chloré, ayant une activité antimicrobienne; b) entre 0,15 et 0,25 % en poids de triclosan (ou d'un sel dudit produit); et c) moins de 0,075 % en poids d'agents chélateurs de l'acide édétique.

Claims

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CLAIMS:
1. An antiseptic bar soap, the bar soap comprising:
a) 0.35 to 0.75% w/w of an antimicrobially active
chlorinated methyl substituted phenol;
b) 0.15 to 0.25% w/w triclosan (or a salt
thereof); and
c) less than 0.075% w/w EDTA chelating agent.
2. An antiseptic bar soap according to claim 1 in
which any chelating agents present are in the soap base of
the bar soap as stabilising agents.
3. An antiseptic bar soap according to claim 1 or
claim 2 in which the chelating agents included as stabilising
agents in the soap base are selected from the group consisting
of ethylene diamine tetraacetic acid (EDTA) and its soluble
salts and [phosphoric acid (1-hydroxy ethylidene) bis].
4. An antiseptic bar soap according to any one of
claims 1 to 3 comprising less than 0.05% w/w EDTA.
5. An antiseptic bar soap according to any one of
claims 1 to 4 in which the antimicrobially active
chlorinated methyl substituted phenol used in the antiseptic
bar soaps of the invention are compounds of formula I
<IMG>
wherein R1 is chlorine or hydrogen, and
R2 is methyl or hydrogen.

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6. An antiseptic bar soap according to claim 5 in
which the compounds of formula I are selected from the group
consisting of 4-chloro-3-methylphenol, 4-chloro-3,5-di-
methylphenol, 2,4-dichloro-3,5-dimethylphenol and mixtures
thereof.
7. An antiseptic bar soap according to claim 5 or
claim 6 comprising from 0.4 to 0.6% w/w of a compound of
formula I, defined in claim 5.
8. An antiseptic bar soap according to claim 5 or
claim 6 comprising 0.5% w/w of a compound of formula I,
defined in claim 5.
9. An antiseptic bar soap according to any one of
claims 1 to 8 which comprises 0.2% w/w triclosan (2-hydroxy-
4,2', 4'-trichloro-diphenyl ether) or a salt thereof.
10. An antiseptic bar soap as claimed in any one of
claims 1 to 9 in which the soap base comprises saponified
fatty acids derived from natural sources.

Description

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ANTISEPTIC SOAP BAR
This invention relates to soap bars having good
antiseptic activity and in particular to soap bars
containing reduced concentrations of chelating
agents.
Many so-called medicated soap products are
available through the world, the majority still being
sold in the form of bar soaps. Such products are
generally referred to as antiseptic if they contain
one or more antimicrobial agents, although their
actual efficacy in use is rarely substantiated.
Thus many products contain higher than
necessary levels of antimicrobial agents (resulting
in increased costs and wastage) or levels that are
not actually effective in use.
It is well known that the activity of many
antimicrobial agents may be improved by the use of
chelating agents and such agents are often used
indiscriminately in such products as antiseptic
soaps.
In fact chelating agents are often used as
stabilising agents in the soap base but are then
added again during manufacture of the finished soap,
in the belief that they will increase antimicrobial
activity.
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However, there are a number of drawbacks
associated with the use of chelating agents, notably
their cost, their potential as irritants and their
environmental impact (eg their effect on river life
etc) .
Thus there is a continuing need for soap bar
products having good, measurable, antiseptic activity
but using the lowest possible concentrations of
antimicrobial agents and chelating agents.
We have now found that a particular combination
of active agents will produce satisfactory antiseptic
activity in a bar soap (including a substantive
effect on the skin) without the use of high levels of
EDTA chelating agent.
There is therefore provided an antiseptic bar
soap comprising:
a) 0.35 to 0.750 w/w of an antimicrobially active
chlorinated methyl substituted phenol;
b) 0.15 to 0.250 w/w triclosan (or a salt
thereof); and
c) less than 0.075° w/w (preferably less than
0.050 w/w) EDTA chelating agent.
Preferably the antiseptic bar soaps of the
present invention contain no chelating agents other
than those included in the soap base as stabilising
agents.
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Chelating agents that may be included as
stabilising agents in the soap base of the antiseptic
bar soaps of the invention include EDTA (ethylene
diamine tetraacetic acid and its soluble salts).
E
Preferably the antiseptic bar soaps of the invention
comprise less than 0.050 w/w EDTA and most preferably
about 0.025° w/w EDTA.
The antimicrobially active chlorinated methyl
substituted phenol used in the antiseptic bar soaps
of the invention are preferably compounds of formula
I
oN
R,
CH3 (I)
30
GI
wherein R1 is chlorine or hydrogen, and
R~ is methyl or hydrogen
Preferred compounds of formula I include PCMC
(4-chloro-3-methylphenol), PCMX (4-chloro-3,5-di-
methylphenol), DCMX (2,4-dichloro-3,5-dimethylphenol)
or mixtures thereof.
Preferably the antiseptic bar soaps of the
invention comprise from 0.4 to 0.6o w/w of a compound
of formula I, more preferably about 0.5o w/w.
Preferably the antiseptic bar soaps of the
invention comprise about 0.2o w/w triclosan
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(2-hydroxy-4,2', 4'-trichloro-diphenyl ether) or a
salt thereof.
The antiseptic bar soaps of the invention also
comprise a conventional soap base, which will
generally comprise saponified fatty acids derived
from natural sources. Examples of suitable soap bases
include an 80:20 mixture of tallow and coconut oil
fatty acids and an 80:20 mixture of distilled palm
oil fatty acids and distilled palm kernel fatty
acids. As stated previously the soap base may further
comprise chelating agents as stabilisers therefore
but it will preferably comprise no more than 0.050
w/w total chelating agents and most preferably no
more than 0.025° w/w EDTA.
The antiseptic bar soaps of the invention may
contain further conventional additives eg. colours,
fragrances (eg pine oil), etc.
The antiseptic bar soaps of the invention may
be produced by any conventional method, such as
mixing of the components together in a hopper, roll
milling, extruding and then cutting and stamping into
the final shape.
40
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The invention will be illustrated by the
following Examples.
Example 1
An antiseptic soap bar is produced to the
following formula:
w/w
PCMX 0.5
Triclosan 0.2
Pine Oil 1.5
(fragrance)
Colours * 0.12
Water * 0.13
DFA Soap to 1000
Chips
DFA Soap Chips:
Distilled fatty acids of Palm Oil 80 +/-30
Distilled fatty acids of palm kernel oil 20 +/- 30
Additions: EDTA tetra sodium 0.0250.
Also 0.2o EHDP which is [phosphoric acid
(1-hydroxy-ethylidene) bis] is added as a stabiliser.
* The colours and water are premixed and closed as a
colour solution.
R
The components are mixed together in a hopper
and these then go through a roll mill, at ambient
temperature and pressure. From there the mixture is
passed into a plodder (extruder) also at ambient
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temperature and then from the extruder it is chopped
and stamped into the requisite shape.
The soap bar has good antiseptic activity and
is substantive on the skin.
Example 2
15
The substantive activity of soap bars of the
invention was demonstrated in the following test.
Standard soap solutions were made by dissolving
a tallow soap base in standard hard water to give a
concentration of 80 (approximately the same
concentration as in lather during hand washing),
Three solutions were prepared each containing 0.04%
w/w PCMX (equivalent to 0.5o w/w in a soap bar) and
either 0.008, 0.016, or 0.024% w/w triclosan
(equivalent to 0.1, 0.2 and 0.3o w/w in a soap bar).
Volunteers dabbed a finger onto the centre of a
Tryptone Soya Agar plate for 30 seconds, washed their
hands for 1 minute in 5m1 of one of the above
solutions, rinsed them, and again dabbed their finger
onto an agar plate.
The agar plates were then swabbed with a
suspension of either Staphylococcus aureus or
Escherichia coli and incubated overnight at 30°C.
They were inspected next day for the presence of a
zone of inhibition.
In all cases the unwashed hands, and those
washed in solutions equivalent to 0.1o w/w triclosan
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containing soaps, produced no zones of inhibition;
indicating no substantive effect on the skin.
In all cases the hands washed in solutions
equivalent to 0.2% or 0.3% w/w triclosan containing
soaps produced distinct zones of inhibition;
indicating a substantive antimicrobial effect on the
skin.
This indicates that more than 0.1o w/w
triclosan is necessary to produce a soap bar with
substantive antiseptic activity, but that more than
0.2o w/w triclosan is not necessary (even in the
absence of added EDTA).
25
35
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